Surface mounted integrated circuit packages, such as a quad flat package (QFP), include an integrated circuit and encapsulating material surrounding the integrated circuit. A plurality of pins, often called leads, such as “gull wing” leads, usually extend from the four sides of the encapsulating material forming the package. These types of integrated circuit devices are surface mounted devices. Socketing is rare and through-hole mounting is usually not possible. The number of pins vary from as low as 30 to as many as over 300 pins along the package periphery and the pitch ranges from 0.4 to 1.0 mm in some examples. The package form may be a flat rectangular body and often is a square body with leads extending along all four sides. There are numerous design variations, which differ usually in the number of leads, their pitch, the package dimensions, and the materials used to construct the package. Materials often are selected to improve or vary the thermal characteristics of the package. Specific design examples include a thin quad flat package and low profile quad flat package.
Some of the quad flat packages, such as a thin quad flat package, may have a poor board level reliability because its leads are not compliant to bending, which has an adverse effect on a drop test and thermal cycling performance for the package. This may also lead to poor circuit board level solder joint reliability between the leads and the circuit board.